In the conventional hand operated ink stamp, the printing die, which is impregnated with ink, is mounted on the lower surface of a die holder contained within an outer housing or casing. A stem or shaft is connected to the upper surface of the die holder and projects upwardly through an opening in the housing and carries a handle. In conventional constructions, as disclosed in U.S. Pat. Nos. 4,022,127 and 4,172,419, the die holder is biased to a raised position, in which the die is disposed out of contact with the surface to be printed, by a compression spring which is located around the stem and is interposed between the casing and the stem or outer handle. By applying a manual force to the upper end of the handle, the spring force will be overcome to move the die downwardly into contact with the surface to be printed. In the conventional spring-biased ink stamp, the spring force is variable and increases as the handle and die are lowered. In some situations, where an operator is required to operate the stamp for long periods, the continual application of manual pressure to overcome the spring force can be fatiguing.
Ball and socket connections between the stem and die holder are known, as disclosed in U.S. Pat. No. 8,388.
It is also known to incorporate an adjustment in an ink stamp in which the position of the lower extremity of the die can be varied with respect to the surface to be printed, as disclosed in U.S. Pat. No. 4,022,127, in order to vary the amount of ink which is imprinted.